Organic farming with gene editing: an oxymoron or tool for sustainable agriculture?

Many advocates of organic farming claim that genetically modified crops are harmful to human health, the environment and the farmers who use them. Biotechnology advocates reaffirming that genetically modified crops are safe, reduce the use of insecticides and enable farmers in developing countries to produce enough food to feed themselves and their families.

Now the parties are chosen to find out whether the new gene editing technology, CRISPR, is really just "GMO 2.0" or a new useful tool for speeding up the plant breeding process. In July, the Court of Justice of the European Union decided that crops grown with CRISPR would be classified as genetically modified. In the United States, meanwhile, the regulatory system makes distinctions between genetic engineering and the specific uses of genome editing.

I am a molecular biologist of plants and I appreciate the impressive potential of CRISPR technologies and genetic engineering. But I do not think it goes against the objectives of organic farming. In fact, biotechnology can help achieve these goals. And while repeating the arguments about genetic engineering seems counterproductive, genome editing can draw both sides to the table for healthy conversation. To understand why, it is necessary to explore the differences between genome modification with CRISPR and genetic engineering.

What is the difference between genetic engineering, CRISPR and mutation selection?

Opponents argue that CRISPR is a sneaky way to persuade the public to eat genetically modified foods. It is tempting to combine CRISPR and genetic engineering in one basket. But even "genetic engineering" and "CRISPR" are too broad to convey what is happening at the genetic level, so let's take a closer look.

In a type of genetic engineering, a gene from an unrelated organism can be introduced into the genome of a plant. For example, much of the eggplant grown in Bangladesh contains a gene for a common bacterium. This gene produces a protein called Bt harmful to insects. By introducing this gene into the eggplant's DNA, the plant itself becomes deadly for eggplant-eating insects and reduces the need for insecticides. Bt is safe for humans. It's as if chocolate makes dogs sick, but does not affect us.

Another type of genetic engineering can move a gene from one variety of a plant species to another variety of that same species. For example, researchers have identified a gene in wild apple trees that makes them resistant to fire blight. They transferred this gene into the apple "Gala Galaxy" to make it resistant to diseases. However, this new apple variety has not been marketed.

Scientists are unable to determine where a gene is inserted into the genome with traditional genetic engineering, although they use DNA sequencing to identify the location after the fact.

On the other hand, CRISPR is a precision tool.

Just like using the "find" function in a word processor to quickly jump to a word or phrase, the CRISPR molecular machinery finds a specific spot in the genome. He cuts both strands of DNA at this place. Because the cut DNA poses a problem to the cell, a repair team is quickly deployed to repair the break. There are two ways to repair the DNA. In one of them, which I call "CRISPR for modification", a new gene can be inserted to connect the cut ends, as if to paste a new sentence into a word processor.

In CRISPR for mutation, the cell repair team tries to pick up the cut DNA strands. Scientists can ask this repair team to modify a few DNA units, or base pairs (A, T, C and G) on the site that was cut, thus creating a small change in DNA called mutation. This technique can be used to modify the behavior of the gene inside the plant. It can also be used to suppress genes internal to the plant that, for example, harm the survival of the plant, such as a gene that increases susceptibility to fungal infections.

Reproductive reproduction, which in my opinion is also a kind of biotechnology, is already used in the production of organic food. In mutation selection, radiation or chemicals are used to randomly modify the DNA of hundreds or thousands of seeds that are then grown in the field. Breeders look for plants of a desired character in the field, such as disease resistance or increased yield. Thousands of new crop varieties have been created and marketed through this process, from quinoa varieties to grapefruit varieties. Mutation selection is considered a traditional breeding technique and therefore does not constitute an "excluded method" for organic farming in the United States.

CRISPR for mutation is closer to mutation selection than to genetic engineering. It creates end products similar to those of mutation breeding, but removes randomness. It does not introduce new DNA. It is a controlled and predictable technique for generating new varieties of useful plants that can withstand disease or withstand adverse environmental conditions.

Lost opportunity – learning about genetic engineering

Most genetically modified traits marketed confer herbicide tolerance or insect resistance in corn, soybean or cotton. Yet there are many other engineering cultures. Some are grown in the field, but most remain in the darkest corners of research labs because of the prohibitive cost of removing regulatory barriers. If the regulatory climate and public perception allow, crops with such valuable characteristics could be produced by CRISPR and become common in our soils and tables.

For example, my counselor at UC Berkeley has developed with colleagues a variety of hypoallergenic wheat. The seeds of this wheat are kept captive in envelopes in the basement of our building, intact for years. A tomato that uses a sweet pepper gene to defend against a bacterial disease, eliminating the need for copper-based pesticides, has struggled to get funding to move forward. Carrots, cassava, lettuce, potatoes and more have been designed for increased nutritional value. These varieties demonstrate the creativity and know-how of researchers to bring new and beneficial traits to life. Why, then, can not I buy hypoallergenic wheat bread at the grocery store?

Relax the power of great agriculture

The research and development of a new genetically engineered crop costs about US $ 100 million in large seed companies. The elimination of regulatory barriers set by the US Department of Agriculture, EPA and / or FDA (depending on the technical nature) takes between five and seven years and an additional $ 35 million. Regulation is important and genetically modified products must be carefully evaluated. But this expense only allows large companies with significant capital to be competitive in this area. The prize eliminates small businesses, university researchers and NGOs. To recover their investment of $ 135 million in crop marketing, companies are developing products to satisfy the largest markets for seed buyers, namely maize, soybean, sugar beet and sugar producers. of cotton.

Research and development costs are much lower with CRISPR because of its accuracy and predictability. Early indications suggest that the use of CRISPR for mutation will not be subject to the same regulatory barriers and costs in the United States. In a press release issued March 28, 2018 by the US Department of Agriculture, "Under Biotech regulation, the USDA does regulate plant regulatory projects that could otherwise have been developed with the help of traditional breeding techniques "if they were developed with approved laboratory procedures

If the EPA and the FDA do the same with reasonable and less expensive regulation, CRISPR could escape the dominant financial empire of large seed companies. Academics, small businesses and NGO researchers can see that work is hard and that intellectual capital generates beneficial products published on the genome that are not always relegated to the basement of research buildings.

Ground of Understanding: CRISPR for Sustainability

In the six years since CRISPR's genome modification capabilities have been unlocked, academics, startups and established companies have announced new agricultural products under development using this technology. Some of them focus on consumer health traits, such as gluten-free or gluten-free wheat for people with celiac disease. Other, like non-browning mushrooms, can reduce food waste.

The persistent drought in California has demonstrated the importance of crop varieties that use water effectively. CRISPR has already produced more productive maize in times of drought, and it is only a matter of time before CRISPR is used to increase the drought tolerance of other crops. Mold-resistant tomatoes could save billions of dollars and eliminate fungicide spraying. A tomato plant that blooms and fruit early could be used in northern latitudes with long days and shorter growing seasons, which will become increasingly important with climate change.

The rules are made, but is the decision final?

In 2016 and 2017, the US National Organic Standards Board (NOSB) voted in favor of excluding all genetically-grown crops from organic certification.

But in my opinion, they should reconsider.

Some organic producers that I interviewed are in agreement. "I see circumstances in which it might be helpful to shorten a process that would require many generations of plants for traditional breeding," said Tom Willey, a farmer emeritus of organic farming native to California. The disruption of natural ecosystems is a major challenge for agriculture, "said Willey," and although the problem may not be fully resolved by genome editing, it could help to "rediscover" in the genomes of the wild ancestors of the cultivated species in order to reconquer the genetic material. " which has been lost over millennia of reproduction for high yields.

Farmers have successfully used traditional breeding to reintroduce such diversity, but "given the urgency created by climate change, we could wisely use CRISPR to accelerate this work," concludes Willey.

Bill Tracy, an organic corn breeder and professor at the University of Wisconsin – Madison, said, "Many CRISPR-induced changes that could occur in nature could have benefits for all types of people." farmers. But, the NOSB has already voted on the issue and the rules are not likely to change without significant pressure. "The question is, what social activity could make things happen," Tracy concludes.

People on all sides of the debate on biotechnology want to maximize human and environmental outcomes. Collaborative problem solving by organic (and conventional) farmers, sustainable agriculture specialists, biotechnologists, and policy makers will make more progress than individual groups acting alone and disdainfully. The obstacles to this may seem important, but they are our own making. Hopefully more people will have the courage to reconnect the projector and let the conversation continue.

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